Yup, Velma is a lesbian. A new film removes any doubt.

In just 13 seconds, a viral clip from the latest “Scooby Doo” movie, released on streaming services this week, settled decades of speculation and fan debates. Velma Dinkley is gay — undoubtedly, unambiguously gay.

The scene, clipped from “Trick or Treat Scooby-Doo!” and shared on Twitter Monday night, starts with Velma as we’ve always seen her: the short brunette bob and bangs; the black, rectangular glasses; that iconic bulky orange turtleneck and maroon pleated skirt. She strides past her fellow sleuths, Daphne Blake and Fred Jones, a box of Scooby snacks in...